Electric switch for incandescent-lamp circuits.



W. B. CROSSLAND. ELECTRIC SWITCH FOR INCANDESCENT LAMP CIRCUITS.

APPLICATION FILED AUG. 9, 1909. 960

s SHEETS-SHEET 1.

Patented June 7, 1910.

A are I 4 v 9W 1 w tlmmm l v vbvwaaw W. B. GROSSLAND. ELECTRIC SWITCHFOR INGANDESOENT LAMP CIRCUITS APPLICATION FILED AUG. 9, 1909.

960,626. Pa ented June 7, 1910.

I 3 S.HEETSSEEBT 2.

IHHH M' g wane sow W. B. CROSSLAND.

ELECTRIC SWITCH FOR INCANDESCENT LAMP CIRCUITS.

APPLICATION FILED AUG. 9, 1909.

Patented June 7, 1910.

3 SHEETS-SHEET 3f 5 t Willlamli. C7088 Q qbi/tneoow Lamp Circuits, ofwhich the following is a current up to normal voltage or gradually ment,'due to the sudden expansion, incident of these violent jerks andUruTEr) STATES P T NT OFFICE.

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Specification of To allwhom it-may concern:

Be it known that I, 'W-I'LLIAM B. Cross lamina citizen ofthe UnitedStates, residing at De Soto, in the county of Jefferson and State ofMissouri, have invented a new and useful Electric 'Switch forIncandescentspecification.

This invention relates to'an electric switch of that type which, afterbeing set in motion, with automaticall cut resistance into 'or out ofcircuit so 5 to gradually bring the reduce it to zero. 1

The principal objectof the present inven-' tion is the revision of anovel switch of this t pe wiich is especially adapted for incan escentlamp circuits whereby the full voltage of the lighting-circuit cannot besud-' denly impressed upon the lamps but, on the contrary, the voltageis gradually brought up to normal to thereby permit the filaments of thelamps to more or less slowly heat, with the result that l'helife of thefilament and the brilliancy thereof is maintained to the greatestpossible extent.

In the operation of tungsten incandescent lamp circuits, I have noticedthe overshot in the lamps, and found, upon investigation, that thefilament, when cold, is of very low resistance and the sudden throwingon of the normal one hundred and ten volts causes a very sudden jerk ormovement of tlie'filato the heating effect of the. current. Thefilaments, if imperfect, cannot stand many soon become broken, and, evenwith perfect filaments, the life and brilliancy are greatly reducedafter a short term of service. Therefore; by a switch as hereinoroposed, the current is gradually increase( in voltage in bringing thelamp'circuit into service, and consequently the jerking movement orvibration of the filaments is avoided. The voltage is also graduallyreduced from normal to zero when cutting the lamp circuit out ofservice, which-has the effect to prolon the life and maintain thebrilliancy of the amp. v

such and other objects in "iew, as willappear as thedescriptioiiproceeds, the

t r P Patented J mi e 7, 1910.

Application am August 9, 909. Serial). 511,994.

parts which will be more fully described hereinafter and set ,forth withparticularity in the claims appended hereto.

In the accompanying drawings, which illustrate certain embodiments ofthe invention, Figure l is a vertical section of the switclrwithparts inelevation and showing the same in open circuit position. Fig. 2 is avertical section showing the parts in closed circuit position. Figs. 3and at are sectional .views of different modified forms of the switch.Fig. 5 is a vertical section of a further modified construction. Fig. 6is a horizontal sectionon line 6-6, Fig. 5.

to'designate corresponding parts throughout the views. w

In carrying out the invention, I employ two telescoping receptacleswhich form ter- "minals between which current is-conducted by a body ofliquid contained in the outer receptacle and the inner receptacle isarranged to be gradually submerged bythe entrance of the liquid throughan opening "in the bottom, whereby a larger area of the inner vessel isexposed to the liquid during the submerging "movement to increase theconductivity and allow more current to flow through the switch, theprinciple of the rhcostat butspecifically ditl'erent therefrom inconstruction. i

In the first form of the invention shown in Figs. 1 and 2,1 designatesan enter metallic vessel which is open at its. top and contains a bodyofliquid 2 such .asavater, and movableverticallyin this vessel Lis aninner inetallic'vessel 3 which can be gradually sunken in orraised outofithe body of water .3. The metallic vessels are connected,respectively, with,condnctors 4 and 5, the latter of which is flexible.so as to permit the inner vessel to rise and fall. These conductors areconnected by a terminal block'G with a lighting circuit 7 havingtungsten or other lam s 8 and a source of current 9. Thus, as the innercylinder is submerged, the current flowing thrt ugh zero to maximumvoltage without the injurious eii'e'cts following from the'full voltageturgs ctr-construction and arrangement ofn [being suddenly thrown on helamp circuit,

switch being similar to an ordinary water the circuit can be graduallybrought ironi Similar reference characters are employed .105according'to the common method ,now'in .use. The inner cylinder is soconstructed as to slowly submerge to effect a gradual cutting out of theresistance. For this purpose, the bottom of the inner vessel has anopenin 10, as clearly shown in Fig. 2, throug which the water 2 entersthe receptacle and allows the latter to sink, the upper end of thevessel being open to allow theair displaced by 'theentering water toescape.

The opening is of restricted area as compared with the cubical contentsof the inner cylinder, so that water will enter slowly to effect gradualdiminution in the buoyancy of the cylinder. The dead weight of the innercylinder is constant at all times, and

hence as the buoyancy decreases, the cylinder will gradually submergemore and more. By properly adjusting the size of the opening, the timerequired for the submerging of the inner vessel can be varied asdesired,

according to the requirements. In order to prevent contact of the innerwith the outer vessel during the opening and closing of the switch, aguide rod 11 is fixed in the outer cylinder in the axial or 'cent erline thereof and this guide rod passes through the inlet opening 10 tothereby prevent lateral movement of the inner vessel to such an extentas to preventshort-circuiting by direct con tact between the vessels.The two vessels are provided attheir upper ends with contact rings 12and 13 whlch engage when the switch is completely closed so that currentwill not have to pass through the water. The inner vessel has a bail 14to which is connected a suspending cable 15 that passes over guide.pulleys loand is equipped with a weight 17. This weight is slightlyheavier than the inner vessel, sothat it will gradually raise the latterout of I the water during the owning movement of the switch. The switchis held open by the weight 17, and when it is desired to closetheswitch, the pull of the weight is removed from the movable element ofthe 'switch by placing the weight on a hook l8, the-weight aving an eye19 for receiving the hook. When the weight is thus hooked up, themovable element is adapted to fall and lowers into the liquid at a ratedepending upon the rate of the flow of the water into the movableeleinent through the opening thereof, until the element reaches closedcircuit position, as shown in Fig. 2. It will thus be seen that the.efiective submerging weight of the movable element as compared with itsdead weight, gradually increases in accordance with the increasingbuoyancy and hence causes the closing of the switch, while the pull oi"the weight 17, when exerted on the cord or cable 16, opens the switch.This pull cannot raise the element suddenly out of the vat-.1 becausethe counterbalance weight is so proportioned to the combined weight ofthe inner cylinder and the water -that is held therein, that it canexert only a gradual pull on the inner cylinder, and this pull-exertedbythe counterbalance weight uniformly increases because the waterin theinner cylinder becomes less and less, and

hence the total weight uniformly diminishes.

It. will thus be seen that the inner cylinder constitutes, in a unitarystructure, a resistance element or conductor of'current and a device forretarding the movement in-bot-h directions, so that the switch can'beneither suddenly opened nor closed. When it is desired to close the lampcircuit, which is open when the switch is 1n the positionshown in Fig.1, it is merely necessary to )lace the weight 17 on the hook 18. Theinner vessel 3 at the same time moves downwardly in thevessel 1 until itencounters the water, when its movement is retarded. As soon asthecontact with the water is made, a weak 'curi-ent passes through thecircuit, but not suiiicient to cause excessive expansion or Vibration ofthe lamp filaments. The inner vessel continues to descend as the waterenters through the opening 10 thereof, whereby a greater surface contactis produced between the said vessel I and water to thereby graduallyincrease the flow of current. \Vhen the descending movementot the vessel3 ceases, the contact rings 12 and 13 will be in engagement as shown inFig.2, so that current of normal voltage will pass through the lightingcircuit. In this manner, the filaments are allowed to gradually heat andglow' until the normal brilliancy is attained. Vhen the circuit is to beopened, the weight is removed from' the hook 18 and allowed to hang bythe cord 25, whereby a tension is exerted on the latter to raise theinner vessel out of the water.- lhis tension, however, is not muchgreater than the resistance offered by the inner vessel and water, sothat the upward movement of the latter is gradual, with the result thatthe conductivity is more and more decreased until finally the circuit isopened by the inner vessel leaving the water. Of course, during thisupward movement of the inner vessel, the water therein flows out throughthe opening or port 10.

In the construction shown in Fig. 3, the' movable element 3' of theswitch is provided with a coating oi porcelain, enamel or othernon-conducting material 20 which is so applied as to leave a V-shapedportion 21 of the metal vessel 3 exposed to contact with the watercontained in the outer vessel 1. The vertex of this V-shaped portion isat the bottom, so as to make initial contact with the water, and as theinner vessel descends, more and more area is exposed to the water andgreater conductivity is provided. Thisarrangement provides for a finergradation in the cutting out of the resistance from the circuit. Theenamel 21 prevents short-circuiting of the: switch by accidental contactbetween the 'tw o vessels, and the guide rod 11 in the first form of theinvention can be dispensed with.

Referring to Rig. 4, the movable element 3" is provided with a.windingof insulated wire'22 wrapped around the outside thereof and which ,hasits lower end connected with a fixed teri' inal piece 23 that is spacedfrom another fi. ed terminal piece 24 which, like the other, fis securedto the bottom of the vemel 3' The terminal piece 24 is con.- nected withthe flexible conductor 25 which has'its outer end connected with thebinding post 26 for the wire 4. This fleirible conductor 25 is ofsufficient length to permit the inner vessel to descend into the outervessel without'interference. The wire 22 has its upper end connectedwith the binding post 27 to which the wire 5'is attached. Thisresistance is cutinto circuit prior to the metallie vessel 3 because theterminal ieces 23 are nearest the water. Hence, as t 1e inner vessel 3"descends, the water between the terminal. pieces 23 and 24 will form abridgin conductor-and the initial flow of current wil take place throughthe resistance wire 22. As the vessel descends into contact with thewater, current will flow through the vessel also, and when the switch isfinally.

closed, the wire and vessel will be short-circuited, because of thecurrent passing through the contact rings 12 and 13. By the use of theresistance coil 22, the range of the switch can be increased. The vessel3" is constructed with" a bottom opening for admitting water and forreceiving the guide rod 28 secured within the outer casing 1.

In Figs. 5 and (3', which show a construction that in some cases mightbe the preferred form of the invention, the currentconducting liquid 30is arranged in a jar 31 which 18 preferably of glass so that the' liquidcan-be observed to notethc evaporation from time to time, and thusenable the attendant to replenish the liquid as needed formaintainingthe normal level. The submergible metallic vessel 32, whichforms one element of the switch, carries the. other element 33. Thevessel 32 is constructed of inner and outer cylindrical shells formingan annular chamber which is closed at the bottom except for one or moreports 34 through which the liquid enters for gradually sink: ing thevessel. The element 33 is insulated from the shells of the vessel 32 inany suitable manner, as for instance, by blocks of insulation 35. Theinner element is connected by a flexible conductor 36 with the bindingst 37 on a contact ring 38 supported on-the ar 31. The vessel 32 is inelectrical connection with a contact ring 39 to which a flexi bleconductor 40 is connected. These conductors 36 and 40 are connectedwith'opposite sides-of an'eleetric circuit and current passes from oneelement of the switch to the other through the liquid when the vessel issubmerged therein. By lowerin the vessel 32 into the liquid, the vesselgradually sinks by reason of'the liquid entering the .port 34, and assoon as the liquid contacts with both elements, a weak current flowsthrough the circuit and this' current becomes stronger and stronger, asmore and more surface of the element is exposed to the liquid. \Vhen thevessel is fully submerged, the ring 39 will engage the ring 38 andthereby short-circuit the liquid and elements. The 'essel is suspendedby a cord &1 guided on p'u1leys42 and provided with a counterbalancingweight 43. .This weight is insuh'icient to raise the .vessel out of thejar 31, and in order to do this,'a supplemental weight 44 is attached tothe weight weight t t is suspended by a. cord 4'5' froma...hook 46. Whenit is desired to open the switch, the

weight 44 is suspended on the weight 43 so that.both' will besufiicientto gradually lift the vessel 32 out of the jar 31. When the switch isclosed, the weight 44; is, of course, detached and can hang on its owncord or be suspended on the book 47,

- From the :foregoing description, takenin connection with theaccompanying drawings,

the advantages of the oonstructionand of the method of operation willbereadily apparent to those skilled in the art to which the inventionappertains, and while I havedescribed the principle of operation of theinvention, together with the apparatus which I now consider to be thebest embodiment thereof, I desire to have it understood that theapparatus shownis merely illustrative,

and that such changes may be made when desired as are within the scopeof the claims appended hereto.

Having thus described the invention, what I claim as new, and desire tosecure by Letters Patent, is

1. Ina switch of the class described, a. combined current resistance anddevice for retarding the opening and closing movement of the switch,such resistance and device consisting of a hollow structure havin arestricted opening through which liquid passes into or out of thestructure during the closing 9r opening of the switch.

2. In a switch of the class described, the combination of a circuit,with a resistancevarying device connected therewith, said deviceincluding a receptacle adapted to hold vessel t rough the said opening.15

-- structure movable intoand out of'the liquid structure formed of metalto serve as a redecreasingthe buoyancy and cause submerging of thestructure. 3. In a variable resistance switch, the combination of avessel adapted to hold a current-conducting liquid, a'combined movableswitch element and retarding device comprising a l IOllOW structure openat its top and having a restricted opening in its-bottom'to permitliquid to pass into and out of the structure as the same moves into andout i of the vessel, and a device for gradually lift- 1 ing thestructure out of the vessel while the liquid asses out of the structureinto the 4. In a variable resistance switch, the combination of aliquid-containing vessel, :1 conductor movable into and out of theliquid for varying the currentflow through the circuit to which theswitch is connected, said conductor constructed to automatically retardthe submerging movement, and -a weight which is inactive during thesubmerging movement of the conductor and is operatively connected withthe latter to withdraw it from the liquid automatically to open theswitch.

-5. A variable resistance switch comprising a liquid-containing vessel,a chambered and having .an opening to permit liquid to pass into and outof the chamber, contacts arranged to engage each other when thestructure is submerged to its fulles't extentto shortecircuit the liquidin the vessel, and a weight adaptedto exert a pull sufficiently greaterthan the combined weight of the structure and liquid therein as togradually remove the structure from the liquid.

6. A switch of the class. described, comprising vessels open at theirtops and mount ed for relative movement one within the other,the-inner-vessel having an opening for admitting liquid contained in theouter vessel during-the submerging of the inner "essel, conductorsconnected with the vessels; and contacts arranged one on the innervessel and one on the outer vessel to engageeach other when the switchis closed to short-circuit the current from the vessel.

7. A variable resistance switch comprising a vessel containing acurrent-miniucting liquid, a hollow vesselof greater specific gravitythan the liquid-and serving as a current resistance, said vessel havingan opening for permitting liquid to enter therein at a. predeterminedrate for submerging the vessel, and a device brought into operation toopen the switch and arranged to exert an upward pull on the inner vesselof" such power as to efl'ecta gradual withdrawal of the vessel from theliquid.

8. A variable resistance switch comprising a. liquid-containing vessel,a chambered sistance and having a restricted opening in its bottom topermitli uid to pass mto and out of the structure, said structure beingof for supporting the weight to relieve the pull thereof from thestructure in the closing of the switch.

. 9.A variable resistance switch comprising aliquid-containing vessel, aresistance movable into and out of the vessel and.having a buoyancywhich automatically. decreases as the resistance moves automaticallyinto the vessel, and a device manually set into operation for exerting apull of gradually increasing strength to solely withdraw the resistancefrom the liquid.

10. A variable resistance switch comprising a liquid-containing vessel,a chambered resistance movable into and out of -the liquid and having anopening through which liquid passes into and out of the chamber, and acounterbalance device consisting of separate weights, one of which isless than the weight of the resistance and both of which are greaterthan the weight of the resistance and the water contained therein whenthe resistance is in closed circuit position for 11. A switch of theclass described comprising separate elements connected with the oppositesides of a circuit and adapted to be brought. into conducting relationby a body .of current-comlucting liquid, one of the elements being inthe form of a hollow ing a hollow metallic element submergible.

in a body of currcnt-conducting liquid and having a restricted portthrough which the 'llqtlld enters or discharges for permitting thegradual sinking or raising of the element, and a circuit connected withthe switch and through which it gradually increasing or decreasingcurrent flows during the movement of the element.

13. A switch of the class described. including a hollow metallicelement. opcnat. its

top andhaving a permanently open port of restricted area comparedwit-lithe cubical contents of the element in its bottom, a container fora cuwent-conducting liquid in which the element gradually sinks asliquid enters the port, and means for connecting the switch with anelectric circuit.

14. A switch of the class described, includarranged to engage each otherwhen the eleing a hollow metallic element open at its ment has reachedthe limit of its submerging a port in its bottom and movement forshort-circuiting the liquid.

- constructed-of inner and outer shells spaced In testimony, thatl,claim the foregoing 5 from each other, a container for a currentasmy'own, I havehei'eto ifiixed my signaconducting liquid in which theelement. ture in the presence of two witnesses. gradually sinks asliquid enters the port, WILLIAM BLAGKNELL-CROSSLAND, means forconnecting the switch. with an Witnesses: electric circuit, and contactscarried respec- Roii'r. B. MUNROE,v

1o tively by the said element and container and top 4 and havin FRANK L.LONG.

